Red Sandstone
Clastic Terrigenous Sedimentary Rock (composed mostly of SiO2 with Fe2O3)
sedimentary
Category
Sedimentary Or Igneous (Secondary Formation)
Browse sedimentary or igneous (secondary formation) specimens identified by the Rock Identifier community.
Sandstone
Arenite (primarily SiO2, silica)
sedimentary
Howlite and Purpurite druzy
Calcium Borosilicate Hydroxide (Howlite) and Manganese Phosphate (Purpurite)
mineral
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
mineral
Yellow Chalcedony
Chalcedony (a cryptocrystalline variety of Quartz, SiO₂)
Mineral
Sandstone (Quartzose Sandstone)
Arenite (SiO2)
sedimentary
Anthracite Coal
Anthracite (a form of coal, primarily carbon)
sedimentary
Banded Jasper (Chert)
Silicon Dioxide (SiO2) - variety of Chalcedony
Sedimentary Rock
Chert (specifically as a lithic artifact/projectile point)
Chert (Silicon dioxide, SiO2)
sedimentary
Chert (Green variety)
Microcrystalline Opaline/Quartz (SiO2)
sedimentary
Granite / Gneiss Complex
Felsic Plutonic Rock (Granite) or High-grade Metamorphic Rock (Gneiss)
igneous/metamorphic
Quartz on Host Rock
Silicon Dioxide (SiO2)
Mineral Specimen
Sandstone (Quartzose Sandstone)
Clastic sedimentary rock (SiO2 primary composition)
sedimentary
Chert (varieties include Flint or Jasper)
Chert (cryptocrystalline quartz; SiO₂)
Sedimentary
Bismuth
Bismuth (Bi)
Mineral
Red Quartz (Druzy)
Silicon Dioxide (SiO2) with Hematite inclusions
mineral
Cockle Shell (Fossil or Recent)
Class Bivalvia, Family Cardiidae (e.g., Cerastoderma edule for common cockle)
Sedimentary (Biogenic, a type of fossil)
Banded Chert (or Banded Jasper)
Silicon Dioxide (SiO2) with Iron Oxide impurities (Hematite/Goethite)
sedimentary
Sandstone (likely Quartzose)
Arenite (primarily SiO2)
sedimentary
Sandstone (Pebble)
Sandstone (arenite, arkose, wacke depending on composition)
sedimentary
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
mineral
Agate
Banded Chalcedony (SiO2)
mineral
Pink Granite
Phaneritic Plutonic Felsic Rock (K-feldspar rich)
igneous
Basalt
Mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
igneous
Marble
Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.
Metamorphic Rock
Red Quartzite
Quartzite (SiO2)
metamorphic
Turritella Agate (Elimia Agate)
Silicified Elimia tenera (formerly misidentified as Turritella)
sedimentary (silicified fossiliferous chalcedony)
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Banded Iron Formation (BIF) / Iron Ore
Banded Iron Formation (composed primarily of Hematite (Fe2O3) and Magnetite (Fe3O4) with Quartz/Chert)
sedimentary
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Banded Gneiss
Gneiss (pronounced "nice")
Metamorphic Rock
Red Sandstone (Siltstone/Mudstone variety)
Ferruginous Sandstone (composed primarily of Quartz with Hematite cementation)
sedimentary
Carnelian
Carnelian (a variety of Chalcedony) - SiO2
mineral
Amazonite
Potassium feldspar (Microcline) - K(AlSi3O8)
mineral
Dalmatian Stone
Dalmatian Jasper (Aplitic Rock)
igneous
Red Jasper
Jasper (Silica-rich Microcrystalline Quartz, SiO2 with Iron Oxide)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3)
sedimentary
Tiger Iron
Tiger Iron (composite of Tiger's Eye, Red Jasper, and Hematite)
metamorphic
Carnelian
Carnelian (Silicon Dioxide, SiO2)
mineral
Porphyritic Basalt or Diabase with Plagioclase Phenocrysts
Porphyritic Basalt or Diabase; Mineral: Plagioclase Feldspar
Igneous
Basalt
Basalt
Igneous